1. Field of the Invention
The present invention relates to eye surgery and, more particularly, to head stabilizers, superior rectus bridle suture fixators and drainage devices particularly useful in cataract surgery and to methods of performing eye surgery while stabilizing a patient's head, fixating superior rectus bridle sutures and securing a drain to drain fluids from the eye.
2. Discussion of the Prior Art
During eye surgery, a patient typically lies on an operating table with the back of the patient's head supported on a head support part of or associated with the operating table. A surgeon is usually positioned adjacent the head support to approach the patient's eye from the top of the patient's head and over the frontal bone, or forehead, of the patient. The head support prevents some movement of the patient's head during surgery; however, the patient's head can still move during surgery due to forces applied by the surgeon or due to movement by the patient since the patient is usually anesthetized locally and, therefore, capable of voluntary head motion. Movement of the patient's head is undesirable during eye surgery and, in particular, cataract surgery, and can lead to substantial complications. During cataract surgery, various surgical instruments are inserted in the eye including instruments for forming an incision in the conjunctiva and limbus, for performing a capsulotomy, for removing the cataractous natural lens, for irrigating and aspirating, and for inserting a lens implant. Accordingly, the patient's head must be held stable to allow precise positioning of the surgical instruments and to avoid damage to surrounding tissue and eye structure from inadvertent contact with the instruments caused by unexpected head movements. Even slight movements of the patient's head during cataract surgery can increase the difficulty of the surgical procedure and can produce adverse consequences due to the precision of the procedure and the small space in which the surgeon has to operate. When the phacoemulsification technique for lens removal is employed, lens tissue is fragmented with an instrument having an ultra-sound tip moving at very high speeds, i.e. approximately 40,000 times per second, while fragmented tissue is aspirated through the instrument. Movement of the patient's head can impair accurate placement of the phacoemulsifier probe resulting in destruction of and/or aspiration of healthy eye tissue. Furthermore, it may be desirable in certain instances for the patient's head to be tilted laterally to one side or the other during surgery to optimize exposure of the eye; however, such head positions are usually precluded during cataract surgery due to the inability to maintain the patient's head at the desired angle for the duration of the surgical procedure, particularly when the patient is anesthetized locally. Head stabilizers for use in eye or cataract surgery have been proposed in applicant's co-pending patent application referenced hereinabove to stabilize and prevent movement of a patient's head during eye surgery. Because it is advantageous to minimize the duration and complexity of surgical procedures of the eye, it is desirable for the head stabilizers to be positioned on a patient simultaneously with surgical drapes used to cover a patient's head and face during eye surgery such that multiple steps of the procedures can be consolidated and thusly simplified.
There is a great need for head restraints and, in particular, head restraints incorporated into surgical drapery, for many other eye procedures performed under local anesthesia such as, for example, photorefractive keratectomy wherein a laser is used to modify corneal curvature to eliminate refractive errors such that any movement of the head during the procedure may comprise the results.
It is also important during eye surgery to immobilize the eye itself; and, accordingly, a bridle suture is usually employed for holding the superior rectus muscle of the eye to restrain and optimally position the eye for surgery. The superior rectus bridle suture is conventionally formed by inserting a needle with a length of suture material attached thereto through the conjunctiva at an entry point located 8 to 10 mm behind the limbus and adjacent a lateral side of the superior rectus, grasping the superior rectus with a muscle forceps, lifting the superior rectus outwardly from the eye, inserting the needle under the raised superior rectus and pulling the needle and suture material through the conjunctiva to exit the eye at a point disposed adjacent an opposing lateral side of the superior rectus. The suture material thusly extends under the superior rectus transversely, or laterally, with ends of the suture material extending from the entry and exit points externally of the eye. The ends of the suture material are grasped and pulled with desired tension in the direction of the patient's forehead such that the superior rectus is lifted by the bridle suture to optimally position the eye in the optic orbit. The superior rectus and, therefore, the eye, is conventionally held in a desired position by securing the ends of the suture material with clamps or tape to the surgical drape covering the patient's head and face or by securing the ends of the suture material to a clamp that is positioned to allow the weight of the clamp to provide tension. Conventional methods for securing the superior rectus bridle suture possess numerous disadvantages including the inability to control the position of the eye, failure to maintain uniform tension on the superior rectus during the surgical procedure, difficulty in changing the position of the eye during the surgical procedure, possible obstruction of the surgical field and decreased reliability due to the increased opportunity for the ends of the suture material to move or become disengaged from the securement site. Bridle suture fixator devices have been proposed in applicant's co-pending patent application referenced hereinabove to allow superior rectus bridle sutures to be fixated with controlled tension along head stabilizers mounting the bridle suture fixator devices. It is desirable for the bridle suture fixator devices to be incorporated into surgical drapery, with or without the head stabilizers, such that the bridle suture fixator devices can be positioned on a patient simultaneously with a surgical drape thusly minimizing the number of steps required in surgical procedures of the eye.
Another very important consideration in eye surgery is to drain fluid that accumulates in the eye during surgery. Excess fluid that accumulates or pools in the eye, either from natural tearing or as the result of saline or other irrigating fluids supplied to the eye during surgery, must be removed from the eye because such fluid can impair the surgical procedure. Where surgical procedures of the eye are conducted with microscopic visualization, excess fluid in the eye can diminish a surgeon's depth of field under the microscope; and, in cataract surgery, excess fluid can obstruct a surgeon's visibility during intraocular lens maneuvers. Excess fluid is commonly removed from the eye during eye surgery by "mopping up" the fluid using small, absorbent spears or by draining the fluid from the eye using a drain communicating with the eye. Where spears are employed, the circulating nurse must continually apply the spears to the eye such that the hands and attention of the nurse are diverted from other tasks and the spears can obstruct the surgeon's view of the eye. The spears also increase the cost of surgical procedures of the eye in that the number of spears used in a single surgical procedure can be considerable. Where drains are used to remove fluid from the eye, there is no way to effectively secure and position the drains and, in particular, to attach or secure the drains to surgical drapery, and the drains cannot be easily replaced and repositioned during eye surgery.